Seatback



FIG. 1 is a top, front, left side perspective view of a seatback, showing my new design;

FIG. 2 is a bottom, front, left side perspective view thereof;

FIG. 3 is a front elevation view thereof;

FIG. 4 is a rear elevation view thereof;

FIG. 5 is a left side elevation view thereof;

FIG. 6 is a top plan view thereof;

FIG. 7 is a bottom plan view thereof;

FIG. 8 is a top, rear, left side perspective view, shown with the environmental subject matter removed for clarity of details otherwise obscured by the broken line disclosure;

FIG. 9 is a bottom, rear, left side perspective view thereof;

FIG. 10 is a left side elevation view thereof;

FIG. 11 is a right side elevation view thereof;

FIG. 12 is a front elevation view thereof;

FIG. 13 is a rear elevation view thereof;

FIG. 14 is a top plan view thereof; and,

FIG. 15 is a bottom plan view thereof.

The broken lines shown in the drawings of the seatback are for the purpose of illustrating the environment and form no part of the claimed design. 

CLAIM The ornamental design for a seatback, as shown and described. 